Differential effects of pre- and/or post-natal d-amphetamine on avoidance response in genetically selected lines of rats.

Effects of pre- and post-natal d-amphetamine on avoidance response were investigated in genetically selected lines of rats. Pregnant animals of the Roman high- and low avoidance (RHA and RLA) lines were administered daily either 3 mg/kg d-amphetamine or physiological saline from day 7 to 20 of gestation. Either-way avoidance learning was studied in prenatally treated offspring over four days of training and subsequently under the effects of four dosages of d-amphetamine. Prenatal intervention with d-amphetamine contributed significantly to avoidance learning over four days of training. A significant genetic line X prenatal treatment X dose response interaction was found in one-way and two-way responses. Results were discussed in terms of inverted-U arousal function, and it is proposed that the prenatal amphetamine intervention may affect baseline levels of physiological arousal. This effect may enhance or impair learning depending upon the nature of the response and the genetic line.